Fine Particulate Matter Levels Below WHO Guidelines Tied to Hospital Admission

MONDAY, Feb. 26, 2024 (HealthDay News) -- Chronic and daily exposure to fine particulate matter (PM_2.5) are associated with an increased risk for hospital admission for cardiovascular disease (CVD) and for natural causes, according to two studies published online Feb. 21 in The BMJ.

Yaguang Wei, Ph.D., from the Harvard T.H. Chan School of Public Health in Boston, and colleagues estimated exposure-response associations between chronic exposure to PM_2.5 and risks for the first hospital admission for major CVD subtypes in a population-based study involving 59,761,494 Medicare fee-for-service beneficiaries aged 65 years and older. The researchers found that three-year average PM_2.5 exposure was associated with increased relative risks for first hospital admissions for ischemic heart disease, cerebrovascular disease, heart failure, cardiomyopathy, arrhythmia, and thoracic and abdominal aortic aneurysms. The exposure-response curve showed a monotonically increased risk for composite CVD in association with PM_2.5: The relative risk was 1.29 at exposures between 9 and 10 µg/m³ versus ≤5 µg/m³ (the World Health Organization air quality guideline for annual PM_2.5 levels).

Yuantong Sun, from the Boston University School of Public Health, and colleagues conducted a case time series study to estimate the excess relative and absolute risks for hospital admissions and emergency department visits associated with daily exposure to PM_2.5 below the new WHO air quality guideline limit using data for 50.1 million commercial and Medicare Advantage beneficiaries. The researchers found that an increase of 10 µg/m³ during the current and previous days was associated with an elevated risk for hospital admissions for natural causes on days when daily PM_2.5 levels were below the new WHO air quality guideline limit of 15 µg/m³ (excess relative risk, 0.91 percent); this increase was exclusively seen in adults aged 65 years and older.

"Our study contributes to the evidence that ambient air pollution is associated with morbidity even at PM_2.5 levels below the current WHO air quality guideline limit," Sun and colleagues write.

Abstract/Full Text - Wei

Abstract/Full Text - Sun